An important use of computers is the transfer of information over a network. Currently, the largest computer network in existence is the INTERNET. The INTERNET is a worldwide interconnection of computer networks that communicate using a common protocol. Millions of computers, from low end personal computers to high-end super computers are coupled to the INTERNET.
In 1989, a new type of information system known as the World-Wide-Web (“the Web”) was introduced to the INTERNET. The Web is a wide-area hypermedia information retrieval system aimed to give wide access to a large universe of WEB documents and other types of http resources.
The architecture of the Web follows a conventional client-server model. The terms “client” and “server” are used to refer to a computer's general role as a requester of data (the client) or provider of data (the server). Under the Web environment, browsers reside in WEB clients and http resources reside in WEB servers. Web clients and Web servers communicate using a protocol called “HYPERTEXT Transfer Protocol” (http). A WEB client opens a connection to a server and initiates an http request for an http resource. The WEB server responds to the request by delivering the requested http resource.
When a server responds to an http request by returning an http resource to a client, the server may also send a piece of state information that the client will store. The state information is often referred to as a “cookie”. Included in the state information (the cookie) is a description of a range of URLs for which the state information should be repeated back to. Thus, when the client sends future http requests to servers that fall within the range of URLs defined by the cookie, the requests will include a transmittal of the current value of the state object. By using this ability to transfer state information back and forth, Web servers can play an active role in transactions between clients and servers.
For purposes of this application, a cookie is referred to as being “valid” for a URL if the URL falls within the range of URL's defined by the cookie.
The use of cookies has enabled the implementation of a large number of WEB based applications. Examples of such applications include online shopping systems that store information about items currently selected by customers, for-fee on-line services that can send back registration information (thereby freeing users from retyping a user-id upon the next connection), and Web sites that can store per-user preferences on the client system and have the client supply those preferences every time the site is later accessed.
A further explanation of cookies can be found in U.S. Pat. No. 5,7444,670, entitled “Persistent client state in a hypertext transfer protocol based client-server system”. That patent is incorporated herein by this reference.